“The content of what the men submitted to the player (Stamatopoulos) was so clear that it should be considered a criminal offer of bribe,” the court said.
Etuhu escaped a jail sentence but was instead fined and sentenced to serve probation without further details being made public.
Etuhu had initially been acquitted by a court in 2018 but that ruling was appealed by prosecutor Johan Lindmark.
However, the Nigerian international said he will be appealing the latest ruling at the Supreme Court.
Etuhu played 20 times for the Super Eagles including Africa Cup of Nations in 2008 and 2010 as well as the World Cup in South Africa.
He also played for several English clubs including Manchester City, Sunderland and Fulham.